Lens blur combined with an alpha pass.
I think I messed up the colors in this one.
I was playing around with the stacker tool when I accidentally hit R with my physgun causing my entire scene to collapse Inception-style. My frames dropped to 0.00001 per second so I tried to take some pictures with it and make a reverse GIF with it.
It kind of looks like a scenebuild being reconstructed, to me at least.
And for some holograms!